<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      //  class 类
      class Perosn {
        constructor() {}
        say() {
          console.log("hello");
        }
        add(x, y) {
          return x + y;
        }
      }

      console.log(typeof Perosn);
    </script>
  </body>
</html>
